1. Field of the Invention
The present invention relates to novel carbon black for an ink and a process for efficiently producing an ink by using such carbon black.
2. Description of the Background
In a carbon black manufacturing plant, it is common to pelletize produced carbon black to facilitate its storage and transportation and also for the purpose of preventing scattering of fine powder during the use by end users. However, in its application to an ink, the dispersibility becomes most important in view of a problem that in the process for preparing an ink, it is impossible to knead carbon black by a strong kneader as used for the preparation of rubber or for incorporating a coloring agent to a resin. Therefore, for the preparation of an ink, carbon black in a powder form having a low bulk density and good dispersibility has been used without pelletizing.
Because of the importance placed on the dispersibility for the preparation of an ink, carbon black used to be packaged in a paper bag in the form of powder without pelletizing. Therefore, a large amount of bulky and easily scattering carbon black had to be unpackaged for the preparation of an ink, which created serious problems from the operational and environmental viewpoint.